perf(matchImei): replace O(N*M) nested ResultSet scan with HashMap lookup

[sauravbhattacharya001]

Summary

Replace the nested-loop device matching in \matchImei.java\ with an in-memory HashMap for O(1) lookups.

Before

• For each event row, the code rewound
  s_device\ to the first row and scanned linearly to find a match
• Complexity: O(events × devices) per pass (sndrnode + srcnode)
• Each matched row triggered an individual \�xecuteUpdate()\

After

• Device table loaded once into a \HashMap<String, String>\ — O(devices)
• Each event row does a single \HashMap.get()\ — O(1)
• Overall: O(events + devices) per pass
• Batch updates (flush every 500 rows) reduce DB round-trips
• Transaction wrapping with rollback on failure
• Extracted \matchAndUpdate()\ to eliminate duplicated sndrnode/srcnode logic
• Removed \SCROLL_INSENSITIVE\ cursors (no longer needed without
  s.first()\ rewind)

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